https://www.microsoft.com/en-us/research/publication/orthogonal-security-with-cipherbase/

Cipherbase is a full-fledged SQL database system that achieves high performance and high data confidentiality by storing and processing strongly encrypted data.

https://github.com/CryptDB/cryptdb

A database system that can process SQL queries over encrypted data.

https://github.com/google/encrypted-bigquery-client

The encrypted BigQuery client is an experimental extension of the BigQuery client. It offers client-side encryption for a subset of query types. Currently it is implemented in Python.

https://www.zetetic.net/sqlcipher/ - github

SQLCipher extends the SQLite database library to add security enhancements that make it more suitable for encrypted local data storage such as on-the-fly encryption, tamper evidence, and key derivation. Based on SQLite, SQLCipher closely tracks SQLite and periodically integrates stable SQLite release features.

https://github.com/Tencent/wcdb

WCDB is an efficient, complete, easy-to-use mobile database framework used in the WeChat application. It's currently available on iOS, macOS and Android.

https://opensource.zerodb.com/ - github

ZeroDB is an end-to-end encrypted database. Data can be stored and queried on untrusted database servers without ever exposing the encryption key. Clients can execute remote queries against the encrypted data without downloading all of it or suffering an excessive performance hit.